What Exactly Happens When You Turn On Your Computer?

When you power on a computer, it goes through a “boot up” process– a term that comes from the word “bootstrap.” Here’s what’s happening in the background—whether you’re using a Windows PC, Mac, or Linux system.

When you press the power button, the computer supplies power to its components—the motherboard, CPU, hard disks, solid state drives, graphics processors, and everything else in the computer.

The piece of hardware that supplies power is known as the “power supply.” Inside a typical desktop PC, it looks like a box at the corner of the case (the yellow thing in the picture above), and it’s where you connect the AC power cord.